Long popular in the South, Oleander gains fans in the North

Oleanders have been a favorite container plant in Europe for more than 400 years. Native to the Mediterranean area, Oleander — Nerium oleander, as they are botanically known — originally produced single pink flowers.

In their native habitat they grew in sandy, well-drained soil. Although in the south they can reach 20 feet in height, they usually grow between 4 and 10 feet.

View full sizeA white Oleander plant not yet in bloom displays a seed pod, identified by lighter green growth in the lower left of the photo.

While they are grown extensively in the southern part of the United States, where the temperatures are warmer than our area, many northern gardeners have discovered that, with a little extra care and planning, they can enjoy the beauty of this charming plant that blooms from spring into fall.

If you are growing Oleander in your garden, now is the time to bring your plant indoors for the winter before the freezing temperatures arrive. An unheated bright porch, basement or garage is ideal for wintering-over tender Oleander plants, as long as the temperature doesn’t drop below freezing.

THEY COME IN COLORS

Oleander blossoms come in shades of white, pink, red, yellow, orange and purple. Some are fragrant and others have two rows of petals producing double flowers.

Oleanders prefer full sun and will have more blooms planted in a sunny spot than in partial shade. They are heat- and drought-tolerant, but if planted in containers will need frequent watering. Drought conditions will cause a reduction in flower production and limit growth rate. A well-watered plant will flower continuously and be constantly growing. Deadheading will encourage blooms.

Oleander leaves are evergreen, similar in appearance to bamboo leaves. If they become light green and decrease in size, it is an indication the plant needs additional fertilizing.

Feed your Oleander in early spring and then once or twice a month during summer. Using a fertilizer that is low in nitrogen and high in phosphorus will encourage blooming and branching, but keep excessive stem growth to a minimum. Super Bloom, Peters Root ‘n Bloom or Blossom Booster would be good choices.

Miracle Gro Bloom Booster or timed-release Osmocote also will work well. Discontinue fertilizing by the end of August, as you don’t want to encourage new growth at this time of year, when it could be affected by the cold autumn weather.

LIMIT EXPOSURE

In spring, when your plants are set outside for the first time, limit their exposure to full sun to only 45 minutes the first day. Add a half-hour each day to gradually get them used to the direct light of the sun. After a week they will have adjusted to the bright light and can take .

As they are tropical plants, Oleanders need to be grown in containers in areas where the temperature falls below freezing. Containers may be sunk into the ground during summer and thus require less watering, but need to be brought indoors when freezing weather arrives. Oleanders are vigorous plants and may need to have both their branches and roots pruned to keep them under control.

Oleanders may be grown as a shrub or small tree. To grow as a tree, remove all stems except one. Keep removing any suckers from the lower branches as soon as they start to sprout. Be aware that if your plant becomes leggy and you prune it, you will be sacrificing some flowers. Oleanders produce blooms on branches that are a year or older, so avoid excessive pruning by limiting cutting back to only the tallest and least-attractive branches.

Photos/Lee GugliadaPink Oleander grows in the garden of Betty LaFemina, past president of the Great Kills Garden Club.

You may find that your Oleander continues to bloom. If pruning is warranted, go ahead and cut off the excess branches, regardless of lost blossoms. Reduce watering when cooler temperatures arrive to avoid root or stem rot. The cooler the temperature, the less water and light the plants will need.

HOW TO PRUNE

When pruning, cut back right above a leaf node — <CM+RTwhich is -RT>the section where the three leaves emerge from the branch. Cut slightly above this point and you will be forcing new branching at each of the leaf nodes, increasing the number of branches threefold. A benefit of having more branches will be the production of more flowers.

Cuttings may be made from late spring to mid-summer. To propagate your Oleander, take an 8- to 10-inch cutting with at least two sets of leaf nodes. Leave the top whorl of leaves, but remove the lower leaves. In order to reduce moisture loss, trim the remaining leaves so that they are about 1-inch long.

At this point you may choose to put your cuttings directly into a container of water or root them in perlite. Roots formed in perlite will be stronger and thicker and avoid transplant shock.

Perlite is a light, sterile media that is moisture-retentive but drains quickly. It is recommended in the Oleander Society’s Handbook. (Yes, there is an International Oleander Society, www.oleander.org, and it hosts an annual Oleander Festival in the middle of May at Moody Gardens in Galveston, Texas.)

Place several cuttings together in a container of moist perlite, making sure most of the cutting is buried deeply. Keep damp and place in a warm area away from direct sun. After several weeks, your cuttings will have rooted, but wait until new leaves are visible before repotting. Place the entire container of cuttings (rooted in perlite) into a pail of lukewarm water and let it soak into the medium, then gently ease the cuttings out of the pot. To eight parts of a peat-based potting mix add one part sand and one part perlite and plant in a clay container.

There are dwarf Oleanders reaching only 5 to 8 inches, petite plants that grow from 2 to 5 feet and miniature varieties that top out at 1 to 2 feet. Although these are more manageable for keeping indoors in cold weather, their blossoms are smaller.

The Castle Manor Garden Club will host an open meeting/card party Wednesday, at 12:30 p.m. in All Saints Episcopal Church hall. The $15 “tea tax” includes a full luncheon and desserts. For reservations call 718-967-3842.

Lee Gugliada is past president of the Great Kills Garden Club and past director of First District Federated Garden Clubs of New York State.